Process and apparatus for separating intermixed divided materials



Oct. 17, 1933. 1,931,008

PROCESS AND APPARATUS FOR SEPARATING INTERMIXED DIvIDED MATERIALS R. PEALE ET AL 2 Sheets-Sheet 1 Filed Sept. 23, 1930 Oct. 17, 1933. R. PEALE ET AL 1,931,008

PROCESS AND APPARATUS FOR SEPARATING INTERMIXED DIVIDED MATERIALS E iled'Sept. 23, 1930 {Sheets-Sheet 2 Patentecl octl 17, 1933 "P A TE-NT' orrlcl-z 1 H I UNITED-STATES The inventionrelates to a novel and useful process and apparatus for separating intermixed,

divided materials, varying relatively greatly in size, and in certain of its features, the invention I has special adaptation to the purification of un sized coal representing difficult problems of purification.

Objects and advantages of the invention will be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities in the appended and combinations pointed out claims. I

structions, arrangements, combinations and improvements herein shown and described.

The accompanying drawings, referred to here in and constituting a part hereof, illustrate'one 20 embodiment of the invention, and together with the description, serve to explain-the principles of the invention; Of the drawings:

Fig. 1 is a side elevation of a form of mecha nism adapted for use in carrying tion;

Fig.2 is a detached plan View of the sub-areal air chamber structure beneath the table; I

out the inventhrough Fig. 1, substantially on the line 3 '-3 of Fig. 1; t o Fig. 4 is a top plan of a tableconstructed in accordance with the invention;

Fig. 5 is a view similar to Fig. 4, and showing the preferred arrangement of variable spacing of the separating partitions and of the .sub,ar.eal

air chambers beneath the deck; N

Fig. 6 is a vertical longitudinal section taken on line 6-6 of Fig. 5; .and I Fig. '7 is a top plan of a table, showing a system of air zoning applied thereto, and omitting the separating partitions.

The invention comprises a'novel and highly ef[i cient separating process of the type wherein lifting and loosening air I currents and vibratory motion coact on the intermixed particulate or divided materials to effect separation thereof. our

process, and the preferred mechanism for praca ticing it, are especially adapted toefliciently sepamaterials which vary relatively greatly in'the 'size range of the pieces or particles; and also-materials of the kind or condition'stated presenting further difficulties in that the specific gravities of the intermixed materialsare very close.

The invention consists in the novel parts, con

Fig. 3 is a transverse, vertical section rate, usually in a single processing, intermixed The pro is especiaily appli ableto. andfinds a wide field for usefulnessljin. 'thebur fi ation of raw, unsized coa s. many of wh h p e ent great difliculties of, the kind indicated. In purifying unsized ocal, that is runoI-min coal, in which 9.

only the very larg lumps have be n c ushed or removed ,(to'av'oid damage to th mechanism the'size of the coal varies from fine dust to pieces several inches in dim nsions, and theslate, roc

phunflandother intermixed impurit s, ike- 6 wise often vary tm' u h a eq a ly wijda ense I sizes. vIn100a.ny ,.s11ci coals the re i e pecific gravities QflJheIcQal and impurities vary, relativei ly little, and thei ravitational splitting point'be-' tweenv the clean coal and the. t s impu 7 tiesisvery close. Certain coals presentfurther dilicullties by .reasdn o the relative p o s of th'e fine and coarse mat r a s a rv ieh p portion offeither ren. ine efli n purific tion exceedingly difficu t. .In th oa gr at dim.- I

culties areduetQ t e Pr n e o a ry hig proportion of impurities in e r f mate:

rials. 1

The present inventio v n in. p ying .f ,difiicult materials .as rawcoals .of the kind described, and possessing the refractory clnirac tensti s .statedjo viates" t a nt f mechanism. time and la or equi drp m j naryfsizing as usua ly pra i and th b e I 'Lquent use of as Separatingtables as there '85 are sizes ofsboal the by pr d ced; wh c hav generally been regarded as essentiallyypreregui- Site to the, purification .of any raw or impure coal,

'andnl kemse avoids the esu a g a b kseoI-the coal;

\ In .ourpresent (novel processthe raw or iinpure coal isfregulably fed ,to constitute, a con- .t-inually -advancing feed, which, as it' advances i over an 'air-pervious deck; is progressively stratiiied and therebyfls'eparated arid purified, through the action of liftin and loosening and floating .air currents, and th flv b t ona d i lination I of the bed. In addition,. preferaibly, quick and lmirnpeded'fractional removalis effected of the impurities .as they separate out and ,settleupon the deck, while mechanical support or ,sustentaltion is provided for thelarger and'large flotant pieces of coal, a QD eq l re y and free discharg joithe fin impuritie Bythese coacting novel actionsfgireesand conditions, the l0 5 p ration of unusua y vidi fic u s d mai is rendered practically/efficient and complete," usu-' ally inasing pro ssx pe a 0 n table-4 BY the main features of the present invention th re is efiectedrfreeand unimpeded passage for 1 10 v r the pieces of settled impurities of all sizes, along the deck and from the bed, without 'wedging or choking, and concurrently therewith iseffected auxiliary sustentation of the larger pieces of flotant purified coal and of the ever thickening stratum-or stream of forwardly flowing purified coal.

In, the commercial practice of our invention,

and carrying out these stated objects or features, the inter-spacing of. the separating partitions,-

that is, the paths or passages along which; the settled impurities are impelled from the bed are variably proportioned in different-parts of the bed to conform to, and to freely accommodate,-

the size of impurities settling on any particular part of the table. 1 That is, in that part ofthe so I " bed or table where the largest impurities settle, the separating partitions are spaced apart sufficiently to permit the largest pieces of impurities to slide alongbetween the separating partitions without wedging or choking. The separating partitions are gradually spaced closer together along the table, proportionally as the'finer and thereby to a large part of the forwardly moving and gradually thickening superior coal stratum or stream. This auxiliary sustentation' is effected by the same variable regulation of the separating partition interspaces. As these become narrower, they still permit the free, sliding transverse passageof the relatively small pieces ofimpurities while the relatively large fiotant coal pieces cannot settle betweenthe separating partitions, but many of them engage ,with and slide across the top edges of the separating partitions, and ,thus directly or indirectly impart auxiliary support to the entire forwardly moving stratum of purified coal, which is at the same time fiotant upon the air currents, ,r H In accordance. with certain features of our invention, and in the present preferred commercial practice thereof, it'is carried out with a bed of the materials that in passing over a'vibrating ,deckor table is subjected to lifting, loosening and-floating air currents which vary gradually,

or by steps, between greatest and leastintensity. To effect this varying aircurrent intensity we preferablyutilize a zoning or gradation of the air perviosity of the table. For most materials we preferably use'the air currents of greatest intensity at the rear of the bed, the intensity decreasing gradually forwardly. f

Further, in the present preferred practice we maintain a transversely inclined bed, from which the'heavy impurities, assoon as they settle from the bed onto the deck, are impelled diagonally toward'and out of the upper side edge of the bed, there being thus effected a continuous fractional discharge of the settled impurities, the larger pieces of which settle out at the rear and by gradually decreasing sizes'forwardly along the table'to aminimum, at or near the front end .of th'ebed Thus a concentration of theseparated heavy materials within the bed is avoided. In such a bed, the superior stratum of purified coal flows freely forwardly along the bed, growingin volume; and thickness, and to a large degree larger pieces tend toward the bottom of 1,931,008 said stratum, with some possible tendency {coward remixture. With a bed and'general process of the kind described, the separating partitions at the rear of the bed and table will be spaced apart sufiiciently far to permit the largest pieces of impurities to slide freely along therebetween, and they will be gradually set closer together forwardly along the table, spaced apart throughout only sufficiently to permit the free passage behind them of the impurities settling at that particular point on the table. Thus, the two steps or functions of our process, as already described, namely, free discharge of the impurities of all sizes, and the auxiliary mechanical sustentation of the larger pieces of coal, especially in areas of lesser air current intensity,

is effected.

In practicing the process in the form or manner just indicated, the strong air currents forced through the rear of the bed provide a loosening action sufficiently intense to cause the largest pieces of the heavy impurities, together with some of the finer, heavy materiaLto rapidly settle on the deck, and as the passages between the separating partitions are adequate, these large settled impurities slide along freely behind the separating partitions, without wedging or choking, and. are discharged, preferably" approximately immediately, fromtheside edge of the bed. Just abovethesa'at this'part of thesinaller impurities, some only a little smaller, anda large part of the coal are still in intermixture and fiotant the strong air currents, and the entire. bed is moving forwardly. Immediately forward of the rear the bed, pieces of the impurities next smaller in size settle out of the bed onto the deck, due to the slight decrease in the current intensity and the naturally slower settlingof finer particles in the rising air currents, and the inter spaces or between the separatingpartitions, although narrower, are sufficiently wide to permit that size. of impurities to slide along freely behind them to discharge at'the' side of the bed; This action continues forwardly along the table, the impurities of lesser and lesser size settling upon the deck due to the lesser and lesser intensity of the air currents. "The inter-- titions, along which the impurities'slide transversely to discharge, are narrower and narrower by: the fiotant superior stratum continuously grows inpurity. Due to the areas of gradually lessening air intensity and the elimination of the bulk of the impure material in the inferior settled stratum, the larger and heavier pieces of coal.

are brought nearer to the bottoinoi the bed and would normally tend to sink behind the separat ing partitions except for the harmonic relation which our invention. maintains between the gradually changing conditions of the bed and the separating partition interspaces. That is, before the conditions just mentioned might obtain in the bed, the inter-spaces orpassages between the separating partitions have become sufiiciently spaces or passages between the separating partively closely set separating partitions,

narrow that thej'larger ofcoal, :at

the bottom of the stratum of coal, are too large to sink between the separating partitions andsothey slide along forwardly over;

the transversely-extending top edges of the partitions at the time being largely supported by the air currents. Due-also to this auxiliary mechanical sustentat'ion ofjthe coal stratum, the. liner refuse, now settled," is not interfered with in its free sliding to discharge behind the rela' remixture of the previouslyseparated' materials 'isprevented, and if there is still remaining intermixture of fines, their separation is facilitated the absence of large pieces-cl coal; as the relatively weak air-cunentswill lift the. fine coal particles over the separating partitions to move forwardly with the bed, while thefinc impurities will move along the intervening passages to discharge at the side edge of the-bed of materials.

To further facilitate and maintainthe sepa'ration and purification especially of the diilicult materials previously described, and in realization ofthe various main objectives stated, namely, to

facilitate the rapid and easy discharge of all sizes 3 proportionately decrease the height ofthe-separating-partitions forwardly in a definite-relation to the decreasing sizeof the separating pieces or particles, and the corresponding increase in the thickness of the stratum of purecoal for- 5 wardly along the'bed. This, in most embodi ments'would comprise a gnadated decrease "in the height of the separating partitions in'harmonywith the decrease in the interspaces of the separating partitions. Such a construction is i shown in Fig. 6 of the drawings. Thus the inter position of the auxiliary mechanical sustaining actionoccurs at successively lower points. forwardly along the bed, but at heights everywhereso that the largest pieces of refuse will pass I unimpededly out of 'the'bed and the stratum of flotant pure coal will move unmixed forwardly. to discharge at thefront of thebed.

-"Referring now-in detail to the present preferred mannerof carrying .outour novel process,

"- and to a. mechanism adapted for carrying it out, same is exemplarily disclosed and described connection with a table of the type shown in the copending application of Richard Peale, SerqNo. 389,722, filed August 31; 1929., although so .ifar as 1 concerns the main features or the invention, it

may be practicedwith other kinds and construcretaining. wall of the table, and an air header 44 tions of tables.

The means for maintainingthe bed of materials, and progressing it forwardly, for vibrating the bed and forcing the lifting andloosening air currents therethrough, may be of any known or suitable form,so far as concerns many features discharge of coal; in .a known manner.

of the present invention.-

In the exemplary embodiment thereof,1a table 5 is shownhaving an air-perviousdeckl, which is preferably transverselyeinclincd upwardly in the direction of travel of the settled heavy impurities and preferably also forwardly in the direction of travel of the superior flotant' stratum. of coal.

. This deck is supported on a suitable yibratable or reciprocable frame which is pivotallymounted at? either side upon two series of backwardlyyand upwardly-inclined pivoted arms 6. The lower ends of the. arms 6 are in. turn pivotally mounted upon a statimaryframe :11, which also consti-c inances I turned to yary'the longitudinalinclination mule Thus,

nally vibratable or reciprocableupon the tiltable plied with apluralityof refuse-dischargingboxes .erably diagonally arrangedatthe forward end along*elther'sideit issupported by a'series of screw ma-mppoams and 14, Many 'known or other-suitable 'l'hese" supports 'may be framejll therewith of the tabledeckl upon which the forwardly-progressing bed of materials is supported. The pivoted supportingarm ii -em der the deck [and its associaxed'parts'longitudi- I frame-11. The tableyibrating means may be of any desired or'convenient mm,- and as eccentric-1'5 is fixed to rotate on a shaft 16, and arod-l'l vlsconnected at one ,end'to the co.- centricand its other end to the'rear end of the table. Thereby the desired reciprocatory Him/6 ment is imparted-tattle table,

Means are provided for maintaining table a forwardly-progressingbediof substantial thickness of the raw 'coal, or other material 1m;- dergoing separation or purification. Means'for maintaining such a bed is shown more or less dis grammatically as including a hopper 18, ovariable speed feed-out device 19.,and'a chute 201m delivering the raw coal, in variably regulated 1106 quantity, to the rear end of the bed or table .1.

The meansfor providing the "loosening and lifting air currents and forcing sameupwardly through the bed may "likewise varywidelyr in form and structure, and as shown, an air cham- 1'10 ber'29 is supported'in the frame 11, andthis air .chambertis connected to'the vibrating table structure by a flexible airy-tight juncture 30. At

its rear end, chamber 29 comm1micates by a flexible connection 31wit h the duct 32 ofa fan 38. 5-

Suitable regulating devices may :be provided if desired, and a own herewith'a; seri s of m-' tatable or 'pivotedvalves 34 :may be provided the chute 32; and additional or other air current regulating means may be employed, as desired. 130

a The separated and settled-refusals preferably dischargedffrom the table by the shortest and quickest route. As embodied; the tableis, sup- 41, arranged along one of the. side the copending applications, and in those, of Kenneth Davis. Thus the settled impurities are impelled diagonally across the table and are expelled from the side edge of the bed. iTheidischarge boxes 41 are locatedralong the side of the upper bed-.

receives air from the fanchute, or the rear part 'of theair chamber, and the air from the header 44 is supplied by flexible conduits 46 to the refuse boxes 41. This'acts to; insure jdischarge of the rock 'and other impurities onily, andv to prevent Y The form of table or deck 1 which wejpreferbly employ, in carrying out our invention is shown in plan in Figs. 4 to 7'.- Ithis table is relatively long and narrow and has a'rcar bed-retaining wall 47 and-sidebed-retaining walls'48-and 49." The spillage edge, 50 for the'purified'coal is' pref- 1-45 of the tablepand preferably occupiesa very large proportion of the: length of'gjthe table. This gives a verylong spillage edge ,for' the purified coal and at the same time permits a. protracted-1 1 p'eriodfor action upon the less"- separable 150.

'tutes f ranie' m the lower non-vibrating part d 1 a table, as. shown and described "in certain pf our components or sizes of the intermixed materials.

The early purified coal will be discharged from the rear part, of the spillage edge 50, but the separatinga'ction will be continued forwardly along I .5 thebed, in connection with the further separating partitions, while thepurifi ed' coal= is dis charged progressively alongthe spillage edge.

The separating partitions :in'rthistype of table are forwardly and transversely-inclined, their rear ends starting some against the rear retaining wall 4J7,v others againstthe side retainingwall 48, and others starting from the spillageedge 50, aswill be clear from Figs. 4 and 5 f I In accordance with our present invention, the

spacing apartof the separating partitions is predetermined for a given table and coal in definite relation to the range of sizes of material treated on the table. That'isthe inter-spaces orpassages between the separating partitions 51 at the rear part ofjthe table will be madesufiiciently wide to permit, the largest pieces of impurities in the particular coal being purified, which settle on this part. of the table, .to pass readily, by friction "and inertia, behind the separatingv partitions to. discharge, without ,wedgingor choking. The inter-spaces or passages between the sepa-.

rating partitions are decreased forwardly along 7 the bed in proportion or harmony with the detion also as an auxiliary mechanical support or .sustention for thelarger particles or pieces in a v superior stratum of purified coal. Proceeding for- I portion of the deckand are slid to discharge I j purification of the'c-oal.

wardly along the table, the separatingflparti tions arenearer and nearer together, and thus the auxiliary mechanical sustaining action is gradually extended to smaller and smaller pieces of thefiotant' superior stratum of purified coal. Not only does the auxiliary mechanicalsustention act to preventsinkingandremixture of'this portion of the purified coal stratum, but it also operates to prevent the larger pieces of coal from-settling in the inter-spacesbetween the separating'partitions, and thus unimpeded pastsage is assured to the relativel'y'small size particles of impuritieswhich have settled on this behind the separatingpartitions; Furthermore, if there is a substantial residue of dirty fines, the separating action is continued onthese behind the separating partitions unimpeded by the 'presence or intermixture of largepieces. Thus, the gradually separating coal fines will rise above 1 theseparatingpartitions and move forwardly to discharge, but the fine impurities will remain behind the partitions and pass transverselyto discharge. All these factors or functions cooperate to effect rapid and complete separation and The present invention operates advantageously in connection with sub-areal air regulation; preferably throughout the entire bed. A form of subarealzoning the same or similar to that shown in i'some of'our earlier copending. applications is preferred. ;A plurality of sub-areal air chambers 52 are formed directly'beneath the air-per'vious deckfl; and regulate or settable means for controlling the passage of, the airthrough the individual sub-arealchambersis provided. --As shown,

the, bottom plate 5'7 of 'therespective sub-areal air chambers'is provided with a plurality of per? forations, which maybe fitted with stoppers or corks 58 to any desired extent, thereby regulating the air current flow through 'theparticular sub:

areal chamber as may be'desired- It will beunderstood, of course, that theform of air-admission controlfor the sub-areal chambers may be varied as-desired..- i

The character of theliftingand loosening air currents forcedthrough the bed of materials undergoing separationmay be widely varied, as

may be found desirable or efiicient. 'In the pres? ent exemplified embodiment, we haveshown a pulsating air current action,-such as'isdisclosed in said copending'application of Richard Peale,

Ser. No. 389,722, and this need-not be described in fulldetail. For this purpose a rotary butter fiy valve or shutter 59 is mounted on a shaftlfii),

journaled transversely across-therair, chamber.

The shutter or butterfly valve 59 rotating within the chamber, alternately leaves it practically wide open anrlxthen closes it practically corn,- pletely, and correspondingly varies the air action through 'thebed. The valve actuating.,mean s comprises a sprocket chain drive 61, which runs over a sprocket wheel 62, fixedon the shaft 60,

'and'overa sprocket wheel 64, fixed on'theshaft 16, already described. By this structure and arrangement, a'puls ating action of the air current along the: bed may be effected, if desired. If the drive for the shutter, 59 is silenced and the shutter removedor left in horizontal position,

the :same mechanism will provide a steady or uniform air current.

The variation in the spacing of. the separating partitions, as an improved;constructional fea- "ture, isharmonized with the structure and position of the sub-areal chambers, andtherebya very .fine regulation of the lifting andloosening air currents in relation to the interspacing be-. tween the separating partitions is effected- Such an arrangement is shownin Fig. 5 of,the-'drawings, where the widest interspacingof separating partitions ,is indicated by numeral 64, and

by the broken line 65. The next degree of interspacing between the separating partitio'nsis indicated by, '70, and theforward separating wall of: the sub-areal chamber is indicated by 71, this wall being inclined in the same direction as the separating partitions. The side walls of the table likewise constitute Walls of the sub-areal air chambers, and there' may be cross 'partitionsbetween such partitions. as 65 and 71,.as shown in Fig. 2 of the drawings, for the chambers 52. Suecessive similar arrangements" of variations in interspacing of separating partitions and the bound ary walls of sub-areal chambers are indicated respectively by'the pairs of reference numerals 72, '73 and '74, and 75 and 76.

In practicing ourinvention, we preferably em- I ploy a table deck of gradated or zoned air perviosity and preferably such a table with the air current intensity decreasing forwardly. In Fig. '7 there is diagrammatically shown a zoning of a table into four degrees of airperviosity, the varying degrees being indicated as A, B, C, and. D. It will be. understood that the gradations may be the forward partition wall of'the separating partition, inclined in the same direction,is indicated when preliminary tests of the run-of-mine coal show a relatively large proportion of coarse heavy material, the rear zone A of greatest air intensity will be accordingly large in area toprovide ade quate air action for the stratificationof the large quantity of coarse impurities. Correspondingly the other zones of air intensity will be calibrated and proportioned according to the relative quan tities of intermediate and smaller sized impuriv coarser impurities have been discharged.

ties in the raw coal.

In the preferred practice of our invention, we

likewisev calibrate the inter-spaces between the separating. partitions with the relative propor tions ofdifferent sizes of the materials in the raw coal to be cleaned. For example, if ,prelim inary tests of the raw coal show that a relatively great proportion of the impurities are in the largest'sizes, the area of the deck occupied by the wider inter-spaces will be correspondingly extensive, and similarly when there is a preponderance offines, the inter-spaces'will be narrow along a relatively greater portion of the deck,

In many cases the inter-spaces will be calibrated in substantially the same proportions as the zones of air-perviosity. For example, as

shown in Figs. 5-and 6, theinter-spaces between separating partitions are arranged in groups of j decreasing widths forwardly along the deck, each group occupying an area corresponding toa zone of air-perviosity. It will be understood, however, that the arrangement andgroupingof the separating partition interspacesfare not neces-,

I sarily dependent upon or calibrated in accordance with the ,air-perviosity zones because with many materials the latter may be determined by factors which do not afiect the layout of, the inter- Similarly, as hereinbefore indicated, the heights of the separating partitions maybe proportioned and graduated in harmony with the general sequence of the separating fprocess Preferably, the separating partitions are caused to decrease in height in much the same relation asthe de crease in the interspaces between the separating partitions. An exemplary embodiment of this feature, is shown in Figurefi, where the heights of the separating partitions are graded down as the interspaces between them also decrease, and

' it will be understood that the principles of calibrating the heights of the separating partitions with respectto the air control and other features of the process will usually be much the same as those applied to the calibration of the interspaces.

The invention in its broader aspects islnot limvided materials varying relatively greatly in size, such as unsized run of the mine coal, whichcomprises forwardly progressing and, progressively stratifying and purifying a bedof the materials by vibration and forcing airtherethrough, pro, gressing aseparated light material as a continuous fiotant stratum toward discharge, and effect ing auxiliary mechanical sustcntionfor a coarser such as unsized run of the mine coal,'comprising forwardly progressing and progressively stratify:

part of said separated flotant light material mov ing toward discharge during the latter stages of ing and purifying a bed of the materials by -vibration and forcing air therethrough, discharge I ing settledheavy impurities from the sideof the I bed, flowing the purified coal forwardly along the bed, and effectingmechanical sustention for the coarses part of the fiotantlcoal after the 3. The process of separating intermiiredltdi vided materials varying relatively greatly in size, such as unsized run of the mine coal, com

y prising forwardly -progressingand progressively stratifying and purifying a bed of the materials ,ties have been discharged. s

4., The process of separating intermixed dividedmaterials varying relatively greatly in size,

such as unsized run of the mine coal, which com prises forwardly progressing and progressively stratifying and purifying a transversely inclined bed of the materials by vibrationand forcing air therethrough, effectingsettlement of the coarser heavy impurities during the earlier stages of separation in the bed, and effecting auxiliary mechanical sustention for a coarser, part of a separated flotant light material movingtowarddischarge during the latter stages of separation in thebed. i I, H

5. A mechanism for separatingintermixed divided materials varying greatly in size, such as raw run-of-mine coaLincluding in combination an air pervious table, means for ,maintaining a forwardly moving bed of the materials upon the table, and means for separating, stratifying and facilitating thedischarge of separatedmaterials which comprise devices for vibratingsthe bed;

devices for forcing loosening and lifting air cure ing at the "feed end of the table to, narrowest spacing at-the discharge end for directing settled heavy, material freely to discharge by friction and inertia and for affording auxiliary mechanical sustention to a material floatedorsusw tainedby said air currents; I i

', 6. A mechanism for separating intermixed di-' vided materials varying greatly in size, such as rawrun-of-mine coal, including in combination an air pervious table, means fo'rmaintaining a forwardly moving bed of the materials upon the table,-and means for separating, stratifying and facilitating'the dischargeof separated materials which comprise devices for vibrating the bed,

devices for forcing loosening and lifting air currents through the bed gradated from relatively great, intensity at the rear to ,relativelysmall intensity'at the forward part of the bed, and

separating partitions spaced more Widely apart in the area of great an current intensity and gradually spaced closer together in areas of decreased air current intensity for directing settled heavyv material freely to discharge by friction and inertia-and for affording auxiliary mechanical' sustention to a material floated or sustained by said air currents;

7. 'A mechanism for separating intermixed di vided materials varying greatly in size, such'as raw runof-mine coal, including in combination v an air pervious table, means for maintaining a forwardly moving bed of the materials upon the table, and means for separating, stratifying and facilitating the discharge of separated materials which comprise devices for vibrating the bed,

devices for forcing loosening and lifting air currents through the bed gradated from relatively great intensity atqthe rear to relatively small intensity at the forward part of thebed, and

separating partitions spaced more widely apart m the area of great 'air-current intensity and gradually spaced closer together in areas of decreased air 'current intensity and gradually decreasing in height with the decrease in interspacing, for directing settled heavy material freely to discharge by friction and inertia and for affording auxiliary mechanical sustention to a material floated or sustained by said air currents.

81A mechanism for separating intermixed di-' vided materials varying greatly in size, such as raw run-of-mine coal, including in combination an air pervious table, means for maintaining a forwardly moving bed of the materials upon the table, and means for separating, stratifying and facilitating the discharge of separated materials which comprise devices for vibrating the bed,

devices for forcing loosening and lifting air currents through the bed in varying degrees of'intensity along the bed, and separating partitions spaced widest apart in the area of greatest air current intensity and spaced gradually closer together in the areas of lesser'air current inten sity.

9. A mechanism for separating intermixed di- A vided materials varying greatly in size, such as raw run-of-mine coal, including in combination an air pervious table, means for maintaining a forwardly moving bed of the materials upon, the table, and means for separating, stratifying and facilitating the discharge of separated mate rialswhich comprise, devices for vibrating the bed, devices for forcing loosening and lifting air currents through the bed in varying degrees of Y intensity along the bed, and separating partitions spaced widest apart in the area of greatest air current intensity and spaced gradually'closer together in the areas of lesser air current intensity, the separating partitions decreasing in,

supplying auxiliary mechanical support to the air-floated coal particles after equivalent size ranges of impurities have been settled." I 11. The process of purifying raw coal var-yin substantially in size which comprises progressing a continuous bed of "said coal alongv an airpervious support and passing lifting and loosening air currents therethrou'gh, causing progressively smaller sizes of heavy impurities to settle to the support and supplying a progressively increasing auxiliary mechanical sustention to pregressively decreasing thelifting' action of said currents to' effect settlement of progressively smaller particles of heavy impurities, and apply-" I ing auxiliary mechanical sustention to coarse flotant coal particles in the areas of decreased air action;

a 13. The process of purifying raw coal varying substantially in size which comprises passing a 1 continuous bed of saidcoal over zones of differvent lifting and loosening air intensities, said intensities being calibrated to effect settlement of different predetermined size ranges of heavy impurities, and applying auxiliary mechanical sustention to the flotant coal pieces of greater size than that of the impurities to be' settled in a iven zone. A y 14. A mechanism for purifying raw' coal of relatively wide size ranges including in combination an air-pervious table, means for progressing a bed of raw coal continuously therealong, means for passing lifting and loosening air cur,- rents through the bed, said air curre'nts'being of, different intensities indifferent areas of the bed, a plurality of separating partitions for guiding settled heavyimpuritie's along the surface of the table to discharge, the spaces between the separating partitions being greater in" the areas of high air intensity and" smaller in the areas of low air intensity.

15. A mechanism for purifying raw coal of relatively wide size ranges including in combinationan air-pervious table, means for progressing a bed of raw coal continuously therealong, means for passing lifting and loosening; aircurrents through the bed, said air currents being of different intensities in different areas of the bed,

a plurality of separating partitions for guiding settled heavy impurities along the surface of the table to discharge, the spaces between "the separating partitions being greater in the areas of high air intensity and smaller in the areas of low air intensity, and the vertical extent of said separating partitions varying in substantially the same manner. j

1 16. A mechanism for separating intermixed divided materialsincluding in combination an air-pervious deck, means for feeding raw material to the deck, means for progressing a bed of raw material along the deck from the feed to'the discharge means and means for effecting a pneu- I air-pervious deck, means forfeeding raw material to the deck, means for discharging separated lighter material from the deck,, means for progressing a bedof raw material along the deck from the feed to the discharge means'and means for effecting a pneumatic stratification and a separation of the stratified materials including devices for passing air currents upwardly'through' the bed and a plurality of parallel separating parpieces and particles varying relatively greatly in size in which the coal is separated from'heavier refuse by lifting the coal on an air cushion above a separating surface in zones of differing air pressure in accordance with thesize of coal to be separated, the step of mechanically supporting above the separating surface in each successive zone the coal of sizes too large to .be supported by the air cushion in this zone. i

v 19. The process of separating heavier refuse of a certain size from a mixture of coal and refuse of various sizes, consisting in supporting above a separating surface the coal of said certain size, and coal and refuse of smaller sizes, on an air cushion, mechanically supporting'above the separating surface coal of larger sizes, and removing the refuse of the certain size which remains supported on theseparating surface.

20." The process'of separating heavier'refuse from a mixture'of coaland refuse, consistingin transporting the mixture through a series of zones in which supporting air cushions are provided, the

air cushions being of successively" decreasing intensity throughout the-series, the air cushion in each zone being adapted to support above a sepa-,

rating surface coal of a certain size and all ,coal

and refuse of smaller size, but not tov support refuse of the certain size,' mechanically support-' ing above the'sep arating surface in each zone coal ofsizes larger than'thecertain size, and withdrawing the refuse'of the certain size which remains supported on the separating surface.

2 l In an apparatus for air-cleaningcoal or similar material comprising aseparating table; means for reciprocating the table,the table having a zoning deck divided into a plurality of diagonally ar-. ranged zones, means for supplying air cushions in the zones of gradually diminishing intensity from the supply to thedeliverytend of thetable, c

pulsion of refuse therethrough while preventing the escapeof coal, a plurality of diagonally posi tioned 'parallel rifiies'. on. the zoning deck fordi-f recting the mi'xedmaterials toward the gates,the spacing between these rifiles being greater in the zones of greater air pressure and less in the zones of lesser air pressure. a i

RICHARD PEALE. REMIBRANDT PEALE, JR.

and outletgates of graduated sizes, one for each zone; at one side of the table for permitting the ex- 

